Apparatus and method for controlling an end-effector assembly

ABSTRACT

An apparatus for controlling an end-effector assembly is provided. The apparatus includes a elongated element configured to engage the end-effector assembly and a drive assembly. A first motion transfer mechanism is disposed at an end of the elongated element. The first motion transfer mechanism is configured to transfer a rotational motion of the elongated element to a motion of the end-effector assembly. A second motion transfer mechanism is disposed at the second end of the elongated element. The second motion transfer mechanism is configured to transfer a motion of the drive assembly to the rotational motion of the elongated element.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

FIELD

The present specification here relates in general to a field of roboticinstruments, and more particularly, to a robotic system for use insurgery.

BACKGROUND

With the gradual transition of medical surgery from the conventionalprocess of making a long incision in the patient's body for performing asurgery to the next generation of surgery, i.e. minimal invasive surgery(MIS), continuous research is going on to develop and integrate roboticinstruments in a system which can be used for MIS purposes. Suchintegration can help a surgeon perform a surgery in a substantiallyerror-free manner, and at the same time work in a realistic environmentthat gives the surgeon a feel of conventional surgery.

SUMMARY

In accordance with an aspect of the invention, there is provided anapparatus for controlling an end-effector assembly. The apparatusincludes a first elongated element having a first end and a second end.The first end of the first elongated element is configured to engage theend-effector assembly. The second end of the first elongated element isconfigured to engage a drive assembly. The apparatus further includes afirst motion transfer mechanism disposed at the first end of the firstelongated element. The first motion transfer mechanism is configured totransfer a rotational motion of the first elongated element to a firstmotion of the end-effector assembly. Furthermore, the apparatus includesa second motion transfer mechanism disposed at the second end of thefirst elongated element. The second motion transfer mechanism isconfigured to transfer a first motion of the drive assembly to therotational motion of the first elongated element.

The apparatus may further include a second elongated element havingfirst and second ends. The first end of the second elongated element maybe configured to engage the end-effector assembly. The second end of thesecond elongated element may be configured to engage the drive assembly.

The second elongated element may be configured to adjust a roll of theend-effector assembly.

The apparatus may further include a third motion transfer mechanismdisposed at the first end of the second elongated element. The thirdmotion transfer mechanism may be configured to transfer a rotationalmotion of the second elongated element to a second motion of theend-effector assembly. The apparatus may also include a fourth motiontransfer mechanism disposed at the second end of the second elongatedelement. The fourth motion transfer mechanism may be configured totransfer a second motion of the drive assembly to the rotational motionof the second elongated element.

The first elongated element may include a first tube.

The second elongated element may include a second tube.

The first elongated element may be nested within the second tube.

The first elongated element may be configured to rotate independentlyfrom the second tube.

The first motion transfer mechanism of the first elongated element mayinclude a plurality of teeth.

The plurality of teeth of the first elongated element may be configuredto mate with a first plurality of teeth of the end-effector assembly.

The third motion transfer mechanism of the second elongated element mayinclude a plurality of teeth.

The plurality of teeth of the second elongated element may be configuredto mate with a second plurality of teeth of the end-effector assembly.

The first elongated element may include a flexible portion.

The first elongated element may include stainless steel.

The flexible portion of the first elongated element may be laser cut toincrease flexibility.

The second elongated element may include a flexible portion.

The second elongated element may include stainless steel.

The flexible portion of the second elongated element may be laser cut toincrease flexibility.

The apparatus may further include a third elongated element having firstand second ends. The first end of the third elongated element may beconfigured to engage the end effector assembly. The second end of thethird elongated element may be configured to engage the drive assembly.

The third elongated element may be configured to adjust a roll of theend-effector assembly.

The third elongated element may include a third tube.

The first and second elongated elements may be nested within the thirdtube.

The first elongated element may be configured to rotate independentlyfrom the third tube.

The apparatus may be configured to provide a coarse motion proximate tothe end-effector assembly.

The apparatus may further include a plurality of cables to control thecoarse motion.

The apparatus may further include a rigid outer cover.

The rigid outer cover may be fixed.

The plurality of cables may be disposed between the rigid outer coverand the first elongated element.

The apparatus may further include an electrical wire extending throughthe first tube.

At least one elongated element may be electrically conductive.

In accordance with another aspect of the invention, there is anend-effector assembly. The assembly includes a first working memberconfigured to engage a first elongated element. Furthermore, theassembly includes a motion transfer mechanism disposed on the firstworking member. The motion transfer mechanism is configured to transfera rotational motion of the first elongated element to a motion of thefirst working member.

The assembly may further include a connector. The connector may beconfigured to connect to a second elongated element. The secondelongated element may provide a rotational motion to adjust a roll ofthe end-effector assembly.

The assembly may further include a second working member configured toengage a second elongated element. In addition, the assembly may furtherinclude a motion transfer mechanism disposed on the second workingmember. The motion transfer mechanism mat be configured to transfer arotational motion of the second elongated element to a motion of thesecond working member.

The motion transfer mechanism of the first working member may include aplurality of teeth.

The plurality of teeth of the first working member may be configured tomate with a plurality of teeth of the first elongated element.

The motion transfer mechanism of the second working member may include aplurality of teeth.

The plurality of teeth of the second working member may be configured tomate with a plurality of teeth of the second elongated element.

The first working member may include a first jaw.

The motion of the first working member may include opening and closingthe first jaw.

The second working member may include a second jaw.

The motion of the second working member may include opening and closingthe second jaw.

In accordance with another aspect of the invention, there is provided adrive assembly configured to connect to a rotatable elongated element.The drive assembly includes a drive mechanism configured to engage therotatable elongated element. Furthermore, the drive assembly includes amotion transfer mechanism disposed on the drive mechanism. The motiontransfer mechanism is configured to transfer a motion of the drivemechanism to a rotational motion of the rotatable elongated element.

The motion transfer mechanism may include a plurality of teeth.

The plurality of teeth may be configured to mate with a plurality ofteeth of the rotatable elongated element.

The drive mechanism may include an electric motor.

In accordance with another aspect of the invention, there is provided arobotic instrument having first and second ends. The robotic instrumentincludes an end-effector assembly disposed at the first end of therobotic instrument, the end-effector assembly comprising a first workingmember. Furthermore, the robotic instrument includes a drive assemblydisposed at the second end of the robotic instrument. In addition, therobotic instrument includes a first elongated element having a first endand a second end, the first end of the first elongated element engagedwith the end-effector assembly and the second end of the first elongatedelement engaged with a drive assembly such that rotation of the firstelongated element causes the first working member of the end-effectorassembly to move.

The robotic instrument may further include a second elongated elementhaving first and second ends. The first end of the second elongatedelement may be engaged with the end-effector assembly. The second end ofthe second elongated element may be engaged with the drive assembly.

Rotation of the second elongated element may adjust a roll of theend-effector assembly.

The end-effector assembly may further include a second working member.

Rotation of the second elongated element may cause the second workingmember of the end-effector assembly to move.

The first elongated element may include a first tube.

The second elongated element may include a second tube.

The first elongated element may be nested within the second tube.

The first elongated element may be connected to the end-effectorassembly with a gear mechanism.

The second elongated element may be connected to the end-effectorassembly with a gear mechanism.

The first elongated element may include a flexible portion.

The first elongated element may include stainless steel.

The flexible portion of the first elongated element may be laser cut toincrease flexibility.

The second elongated element may include a flexible portion.

The second elongated element may include stainless steel.

The flexible portion of the second elongated element may be laser cut toincrease flexibility.

The robotic instrument may further include a third elongated elementhaving first and second ends. The first end of the third elongatedelement may be configured to engage the end-effector assembly. Thesecond end of the third elongated element may be configured to engagethe drive assembly.

The third elongated element may be configured to adjust a roll of theend-effector assembly.

The third elongated element may include a third tube.

The first and second elongated elements may be nested within the thirdtube.

The robotic instrument may be configured to provide a coarse motionproximate to the end-effector assembly.

The robotic instrument may further include a plurality of cables tocontrol the coarse motion.

The robotic instrument may further include a rigid outer cover.

The rigid outer cover may be fixed.

The plurality of cables may be disposed between the rigid outer coverand the first elongated element.

The robotic instrument may further include an electrical wire extendingthrough the first tube.

At least one elongated element may be electrically conductive.

The robotic instrument may further include a fixed outer cover.

In accordance with an aspect of the invention, there is provided amethod for controlling an end-effector assembly at the end of a roboticinstrument. The method involves rotating a first elongated element usinga drive assembly, wherein the first elongated element is engaged withthe drive assembly. The method further involves transferring arotational motion of the first elongated element to move a first workingmember of the end-effector assembly.

The method may further involve rotating a second elongated element usingthe drive assembly. The second elongated element may be engaged with thedrive assembly.

Rotating the second elongated element may adjust a roll of theend-effector assembly.

Rotating the second elongated element may move a second working memberof the end-effector assembly.

Rotating a first elongated element may involve rotating a first tube.

Rotating a second elongated element may involve rotating a second tube.

The first elongated element may be nested within the second tube.

The method may further involve flexing a flexible portion of the firstelongated element.

The first elongated element may include stainless steel.

The flexible portion of the first elongated element may be laser cut toincrease flexibility.

The method may further involve flexing a flexible portion of the secondelongated element.

The second elongated element may include stainless steel.

The flexible portion of the second elongated element may be laser cut toincrease flexibility.

The method may further involve rotating a third elongated element usingthe drive assembly. The third elongated element may be engaged with thedrive assembly and wherein rotating the third elongated element adjustsa roll of the end-effector assembly.

The third elongated element may include a third tube.

The first and second elongated elements may be nested within the thirdtube.

The method may further involve controlling a coarse motion of the firstend of the first elongated element.

Controlling may involve applying tension to a plurality of cables.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made, by way of example only, to the accompanyingdrawings in which:

FIG. 1 is a perspective view of an operating theater according to anembodiment;

FIG. 2 is a perspective view of a robotic instrument in accordance withan embodiment;

FIG. 3 is another perspective view of the robotic instrument with theworking member in an open position in accordance with the embodiment ofFIG. 2;

FIG. 4 is perspective view of a drive assembly of the robotic instrumentin accordance with the embodiment of FIG. 2;

FIG. 5 is a perspective view of a robotic instrument in accordance withanother embodiment;

FIG. 6 is another perspective view of the robotic instrument inaccordance with the embodiment of FIG. 5 with a cutaway portion;

FIG. 7 is a cross sectional view of a robotic instrument in accordancewith the embodiment of FIG. 5 through the line A-A;

FIG. 8 is perspective view of a drive assembly of the robotic instrumentin accordance with the embodiment of FIG. 5;

FIG. 9 is a view showing the a movement of the robotic instrument ofFIG. 5;

FIG. 10 is a perspective view of a robotic instrument in accordance withanother embodiment;

FIG. 11 is another perspective view of the robotic instrument inaccordance with the embodiment of FIG. 10;

FIG. 12 is a perspective view of a robotic instrument in accordance withanother embodiment;

FIG. 13 is another perspective view of the robotic instrument inaccordance with the embodiment of FIG. 12 with a cutaway portion;

FIG. 14 is a cross sectional view of a robotic instrument in accordancewith the embodiment of FIG. 12 through the line B-8;

FIG. 15 is perspective view of a drive assembly of the roboticinstrument in accordance with the embodiment of FIG. 12;

FIG. 16 is a view showing the a movement of the robotic instrument ofFIG. 12;

FIG. 17 is a perspective view of a robotic instrument in accordance withanother embodiment;

FIG. 18 is another perspective view of the robotic instrument inaccordance with the embodiment of FIG. 17 with a cutaway portion;

FIG. 19 is a perspective view of a robotic instrument in accordance withanother embodiment;

FIG. 20 is a perspective view showing the a movement of a roboticinstrument in accordance with another embodiment;

FIG. 21 is a perspective view showing the another movement of a roboticinstrument in accordance with the embodiment of FIG. 20;

FIG. 22 is a perspective view showing the a movement of a roboticinstrument in accordance with another embodiment;

FIG. 23 is a perspective view showing the another movement of a roboticinstrument in accordance with the embodiment of FIG. 22;

FIG. 24 is a perspective view of a robotic instrument in accordance withanother embodiment; and

FIG. 25 is a perspective view of a portion of a robotic instrument inaccordance with another embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to FIG. 1, a schematic representation of an operating theaterfor Minimal Invasive Surgery (MIS) is shown at 100. It is to beunderstood that the operating theater 100 is purely exemplary and itwill be apparent to those skilled in the art that a variety of operatingtheaters are contemplated. The operating theater 100 includes a surgicaltable 104 and a surgical system 108. The surgical table 104 includes asurface 112 supported by a base 116. It is to be understood that thesurgical table 104 is not particularly limited to any particularstructural configuration. A patient P rests on the surface 112. Thesurgical system 108 includes a base unit 120, an input device 124, arobotic arm 128, and at least one robotic instrument 132 with anend-effector assembly 136.

In a present embodiment, the base unit 120 is generally configured tosupport and control the robotic arm 128 in response to input controlsignals from input device 124 under the control of a surgeon or othermedical professional. In terms of providing physical support, the baseunit 120 is mechanically structured to support the robotic arm 128, therobotic instrument 132, and their associated movements. For example, thebase unit 120 can be bolted to a fixed structure such as a wall, floor,or ceiling. Alternatively, the base unit 120 can have a mass and ageometry such that when base unit 120 is free-standing, it will supportthe robotic arm 128. In some embodiments, the base unit 120 can includea moveable cart to provide easy movement of the base unit 120 around theoperating theater 100. In terms of providing control, the base unit 120can include mechanical controls (not shown), or electrical controls (notshown), or both. For example, mechanical controls can include gears,cables or other motion transfer mechanisms (not shown) connected to amotor. Other mechanical controls can also involve hydraulics.Alternatively, in embodiments where a motor is disposed in the roboticarm 128 or the robotic instrument 132, the base unit 120 can supply onlyelectrical control signals to operate the motors in the robotic arm 128or the robotic instrument 132.

Referring again to FIG. 1, the robotic arm 128 is generally configuredto support the robotic instrument 132. In terms of providing physicalsupport, the robotic arm 128 is mechanically structured to support therobotic instrument 132, and its associated movement. For example, therobotic arm 128 is constructed such that it is rigid enough to besuspended above the patient P. In addition, the robotic arm 128 can beconfigured so that robotic instrument 132 is positionable in relation tothe base unit 120 and surface 112. For example, the robotic arm 128 caninclude a moveable joint (not shown) for providing a pivotal degree offreedom. In another example, the robotic arm 128 can include a railsystem (not shown) for linear movement of the robotic instrument 132. Itwill now be understood that the movement of the robotic arm 128 iscontrolled by the base unit 120 through various controls describedabove.

In general terms, the robotic instrument 132 and its end-effectorassembly 136 are generally configured for performing MIS responsive toinputs from the input device 124 mediated by the base unit 120 and therobotic arm 128. However, it is to be re-emphasized that the structureshown in FIG. 1 is a schematic, non-limiting representation only. Forexample, although only one robotic arm 128 is shown in FIG. 1, it is tobe understood that the surgical system 108 can be modified to include aplurality of robotic arms 128, each robotic arm 128 having its own aseparate robotic instrument 132 and separate end-effector assembly 136.Furthermore, it is also to be understood that where the surgical system108 includes a plurality of robotic arms 128 with robotic instruments132, each robotic arm 128 or robotic instrument 132 can have differentstructures. Indeed, a plurality of different configurations of roboticinstrument 132 are contemplated herein.

In use, the robotic instrument 132 is configured to provide theend-effector assembly 136 with at least one degree of freedom. A degreeof freedom refers to an ability of an end effector assembly 136 to moveaccording to a specific motion. For example, a degree of freedom caninclude a rotation of the end-effector assembly 136 or a componentthereof about a single axis. Therefore, for each axis of rotation, theend-effector assembly 136 is said to have a unique degree of freedom.Another example of a degree of freedom can include a translationalmovement along a path. It will now be apparent that each additionaldegree of freedom increases the versatility of the end-effector assembly136. By providing more degrees of freedom, it will be possible toposition the end-effector assembly 136 in a wider variety of positionsor locations to, for example, reach around obstacles.

Referring to FIG. 2, an embodiment of the robotic instrument 132 isshown in greater detail. It is to be understood that the roboticinstrument 132 is purely exemplary and it will be apparent to thoseskilled in the art that a variety of robotic instruments arecontemplated including other embodiments discussed in greater detailbelow. The robotic instrument 132 includes an end-effector assembly 136,an elongated element 140 and a drive assembly 144.

In the present embodiment, the end-effector assembly 136 is shown inFIG. 3. The end-effector assembly 136 is generally configured tointeract with the patient P during MIS. The end-effector assembly 136includes two working members 148 and 152. The end-effector assembly 136also includes a motion transfer mechanism. In the present embodiment,the transfer mechanism is a gear 156 having a plurality of teeth. Inparticular, the gear 156 of the present embodiment is a bevel gear.However, other embodiments may use other types of gears. It is to beunderstood that the end-effector assembly 136, including the workingmembers 148 and 152, is not particularly limited to any material andthat several different types of materials are contemplated. Theend-effector assembly 136 is typically constructed from materials whichcan withstand the harsh conditions of a sterilization process carriedout prior to an actual surgery. Some examples of suitable materialsinclude stainless steel, such as surgical stainless steel, titanium,plastics, composites and other materials commonly used in surgicalinstruments. The exact configuration of working members 148 and 152 isnot particularly limited. In the present embodiment shown in FIGS. 2-4,the working members 148 and 152 are the jaws of forceps. In otherembodiments, the working members can be other surgical instruments suchas scissors, blades, graspers, clip appliers, staplers, retractors,clamps or bipolar cauterizers or combinations thereof. Also, in otherembodiments the end-effector assembly may include a single workingmember such as imaging equipment, such as a camera or light source, orsurgical instruments such as scalpels, hooks, needles, catheters,spatulas or mono-polar cauterizers.

Referring again to FIG. 2, the elongated element 140 extends between theend effector assembly 136 and the drive assembly 144. The elongatedelement 140 is generally configured to support and control theend-effector assembly 136. It is to be understood that the elongatedelement 140 is not particularly limited to any material and that severaldifferent types of surgical-grade materials are contemplated. Examplesof surgical grade materials include surgical stainless steel, titanium,plastics, composites and other materials commonly used in surgery, whichin general can withstand sterilization. The elongated element 140includes two motion transfer mechanisms. In the present embodiment, themotion transfer mechanisms include first and second gears 160 and 164(FIG. 4) each having a plurality of teeth and disposed at opposite endsof the elongated element 140. The first gear 160 is configured to matewith the gear 156 of the end-effector assembly 136. In certainembodiments, the elongated element 140 is rigid, such that applying arotational torque about an axis 168 at the second gear 164 will causethe elongated element 140 to rotate without significant deformation atthe first gear 160. It will now be appreciated that the first gear 160is configured to transfer rotational motion of the elongated element 140to the gear 156 of the end-effector assembly 136 to move the workingmember 148.

The drive assembly 144 of the present embodiment is shown in greaterdetail in FIG. 4. The drive assembly 144 includes a motion transfermechanism. In the present embodiment, the transfer mechanism is a drivegear 172 having a plurality of teeth. The drive gear 172 is configuredto mate with the second gear 164 of the elongated element 140. It willnow be appreciated that the drive gear 172 is configured to transfermotion from the drive assembly 144 to a rotational motion of theelongated element 140 about the axis 168 by applying a rotational torqueto the second gear 164 of the elongated element 140. The drive gear 172can be driven by various means, such as via an electric motor (notshown), hydraulics, pneumatics, magnetic actuators or a piezoelectricmotor. It will now be appreciated that the motion used to rotate thedrive gear 172 does not need to be a rotational motion and can be anytype of motion capable of applying a torque to rotate the drive gear172.

In operation, the present embodiment of the robotic instrument 132controls the movement of the working member 148 of the end-effectorassembly 136. A source of motion in the drive assembly rotates the drivegear 172. The drive gear 172 engages the second gear 164 of theelongated element 140. Therefore, as the drive gear 172 is rotated,engagement to second gear 164 of the elongated element 140 will causethe elongated element to rotate about the axis 168. The rotation of theelongated element 140 will cause a corresponding rotation of the firstgear 160. The first gear 160 engages the gear 156 of the end-effectorassembly 136. Therefore, as the first gear 160 rotates, engagement tothe gear 156 of the end-effector assembly 136 will cause the workingmember 148 to pivot about a first axis 176 to open and close the jaw. Itwill now be appreciated by a person skilled in the art with the benefitof this description and the accompanying drawings that the workingmember 152 can be fixed or can also be pivoted about the first axis 176.When the working member 152 is controlled by the elongated element 140,rotating the elongated element 140 can cause the working members 148 and152 to open or close. For example, if the first gear 160 engages bothworking members 148 and 152 on opposite sides of the first gear 160, thefirst gear 160 can apply opposite torques to working members 148 and 152about the first axis 176. By applying opposite torques, the workingmembers 148 and 152 may be opened and closed by rotating the elongatedelement 140. It is to be understood that when both working members 148and 152 are controlled by the elongated element 140, the working members148 and 152 will close at the same position relative to the elongatedelement 140.

Therefore, in embodiments of end-effector assemblies comprising at leastone jaw, such as the present embodiment, the first motion ischaracterized by the rotation motion within the same plane in which ajaw opens and closes.

It will now be appreciated that the first rotational motion provides adegree of freedom which involves rotating the end-effector assembly 136about a first axis 176. However, it will now be appreciated that thefirst axis 176 will be substantially perpendicular to the axis 168nearest to the first axis 176. In other words, the first axis 176 is notnecessarily fixed with respect to the surface 112 or the surgical system108.

In general terms, the robotic instrument 132 is generally configured totransfer a motion from a source in the drive assembly 144 to control theworking member 148 of the end effector assembly 136. It is to bere-emphasized that the structure shown in FIGS. 2 to 4 is a non-limitingrepresentation only. Notwithstanding the specific example, it is to beunderstood that other mechanically equivalent structures and motiontransfer mechanisms can be devised to perform the same function as therobotic instrument 132. For example, other motion transfer mechanismscan include frictional engagement, belts, or cables or combinationsthereof. Furthermore, although the motion of the drive gear 172 is arotational motion, it is not necessary that this be a rotational motionas discussed above. Other types of motion, such as a linear motion, arealso contemplated. Furthermore, in some embodiments, the drive gear 172and the second gear 164 of the elongated element 140 may be omitted andthe elongated element 140 may be directly driven by a motor.

Referring to FIGS. 5 to 9, another embodiment of a robotic instrument132 a is shown. Like components of the robotic instrument 132 a bearlike reference to their counterparts in the robotic instrument 132,except followed by the suffix “a”. The robotic instrument 132 a includesan end-effector assembly 136 a, first and second elongated elements 140a and 180 a respectively, and a drive assembly 144 a.

In the present embodiment, the end-effector assembly 136 a is shown ingreater detail in FIG. 6. The end-effector assembly 136 a is generallyconfigured to interact with the patient P during MIS. The end-effectorassembly 136 a includes two working members 148 a and 152 a. Theend-effector assembly 136 a also includes two motion transfermechanisms. In the present embodiment, the transfer mechanisms are firstand second gears 156 a and 184 a each having a plurality of teeth. It isto be understood that the end-effector assembly 136 a, including theworking members 148 a and 152 a, is not particularly limited to anymaterial and that several different types of materials are contemplatedsuch as those contemplated for the end-effector assembly 136. The exactconfiguration of working members 148 a and 152 a is not particularlylimited. In the present embodiment shown in FIGS. 5 to 9, the workingmembers 148 a and 152 a are jaws of forceps. In other embodiments, theworking members can be other surgical instruments such as scissors,blades, graspers, clip appliers, staplers, retractors, clamps orbi-polar cauterizers or combinations thereof. Also, in other embodimentsthe end effector assembly may include a single working member such asimaging equipment, such as a camera or light source, or surgicalinstruments such as scalpels, hooks, needles, catheters, spatulas ormono-polar cauterizers.

Referring to FIG. 5, the first and second elongated elements 140 a and180 a extend between the end-effector assembly 136 a and the driveassembly 144 a. The first and second elongated elements 140 a and 180 aare generally configured to support and control the end-effectorassembly 136 a. It is to be understood that the first and secondelongated elements 140 a and 180 a are not particularly limited to anyone type material and that several different types of surgical-gradematerials are contemplated such as those contemplated for the elongatedelement 140. The first and second elongated elements 140 a and 180 aeach include two motion transfer mechanisms. In the present embodiment,the motion transfer mechanisms of the first elongated element 140 ainclude first and second gears 160 a and 164 a each having a pluralityof teeth and disposed at opposite ends of the elongated element 140 a.The first gear 160 a is configured to mate with the first gear 156 a ofthe end-effector assembly 136 a. The motion transfer mechanisms of thesecond elongated element 180 a include first and second gears 188 a and192 a each having a plurality of teeth and each disposed at oppositeends of the second elongated element 180 a. The first gear 188 a isconfigured to mate with the second gear 184 a of the end-effectorassembly 136 a. In certain embodiments, the first and second elongatedelements 140 a and 180 a are each rigid, such that independentlyapplying a rotational torque about an axis 168 a at the second gears 164a and 192 a will cause the first and second elongated elements 140 a and180 a, respectively, to rotate independently from each other withoutsignificant deformation. It will now be appreciated that the first gears160 a and 188 a are configured to transfer rotational motion of thefirst and second elongated elements 140 a and 180 a to the first andsecond gears 156 a and 184 a of the end-effector assembly 136 a to move,independently, the working members 148 a and 152 a, respectively.

Referring to FIG. 6, the first gears 160 a and 188 a of the presentembodiment are sector gears. Using sector gears in the presentembodiment permits both of the first gears 160 a anti 188 a to rotatewithin a range of angles in the same plane to independently control theworking members 148 a and 152 a. It is to be understood that the firstgears 160 a and 188 a are not limited to sector gears and that otherother embodiments are contemplated. For example, the first gears 160 aand 188 a can be modified to be other types of gears such as nestedcircular gear racks.

Referring to FIG. 8, the drive assembly 144 a of the present embodimentis shown in greater detail in FIG. 8. The drive assembly 144 includestwo motion transfer mechanisms. In the present embodiment, the transfermechanisms are first and second drive gears 172 a and 196 a, each havinga plurality of teeth. The first and second drive gears 172 a and 196 aare configured to mate with the gears 164 a and 192 a respectively. Itwill now be appreciated that the first and second drive gears 172 a and196 a are configured to transfer, independently, motion from the driveassembly 144 a to a rotational motion of the first and second elongatedelements 140 a and 180 a about the axis 168 a, respectively, by applyinga rotational torque to the second gears 164 a and 192 a, respectively.The first and second drive gears 172 a and 196 a can be driven,independently, by various means, such as those discussed above inconnection with drive assembly 144.

In operation, the present embodiment of the robotic instrument 132 acontrols the movement of the working members 148 a and 152 a of theend-effector assembly 136 a. A source of motion in the drive assemblyrotates the first and second drive gears 172 a and 196 a. The first andsecond drive gears 172 a and 196 a engage the second gears 164 a and 192a of the elongated elements 140 a and 180 a, respectively. Therefore, asthe drive gear 172 a is rotated, engagement to second gear 164 a of thefirst elongated element 140 a will cause the first elongated element torotate about the axis 168 a. The rotation of the first elongated element140 a will cause a corresponding rotation of the first gear 160 a. Thefirst gear 160 a engages the first gear 156 a of the end-effectorassembly 136 a. Therefore, as the first gear 160 a rotates, engagementto the first gear 156 a of the end-effector assembly 136 a will causethe working member 148 a to pivot about a first axis 176 a. Similarly,as the drive gear 196 a is rotated, engagement to second gear 192 a ofthe second elongated element 180 a will cause the second elongatedelement to rotate about the axis 168 a. The rotation of the secondelongated element 180 a will cause a corresponding rotation of the firstgear 188 a. The first gear 188 a engages the second gear 184 a of theend-effector assembly 136 a. Therefore, as the first gear 188 a rotates,engagement to the second gear 184 a of the end-effector assembly 136 awill cause the working member 152 a to pivot about the first axis 176 a.

It will now be appreciated by a person skilled in the art with thebenefit of this description and the accompanying drawings that, in thepresent embodiment, the working members 148 a and 152 a can be pivotedabout the first axis 176 a independently to open and close the jaw.

It will now be appreciated that the independent control of the workingmembers 148 a and 152 a provides an addition degree of freedom over therobotic instrument 132 which involves rotating the working members 148 aand 152 a about the first axis 176 a as shown in FIG. 9. Therefore, theindependent control of the working members 148 a and 152 a allows theworking members to open and close over a range of angles about the firstaxis 176 a, whereas the working members 148 and 152 were only able toopen can close at a fixed angle.

Variations are contemplated. For example, although the presentembodiment shows the first and second elongated elements 140 a and 180 aare nested tubes, it is to be understood that the embodiment is purelyexemplary and it will be apparent to those skilled in the art that avariety of different configurations of the first and second elongatedelements 140 a and 180 a are contemplated. For example, the firstelongated element 140 a can be modified such that it is not a hollowtube. Furthermore, it is also contemplated that the second elongatedelement 180 a can be modified into a solid rod in some embodiments. Inother embodiments, the first and second elongated elements 140 a and 180a, respectively, can be modified such that they are not nested andinstead are parallel and adjacent.

Referring to FIGS. 10 and 11, another embodiment of a robotic instrument132 b is shown Like components of the robotic instrument 132 b bear likereference to their counterparts in the robotic instruments 132 and 132a, except followed by the suffix “b”. The robotic instrument 132 bincludes an end-effector assembly 136 b, first and second elongatedelements 140 b and 180 b respectively, and a drive assembly (not shown).

The end-effector assembly 136 b is generally configured to interact withthe patient P during MIS. The end-effector assembly 136 b includes twoworking members 148 b and 152 b. The end-effector assembly 136 b alsoincludes two motion transfer mechanisms. In the present embodiment, themotion transfer mechanisms of the end-effector assembly 136 b include afirst rotating element 157 b and a second rotating element 185 b. Afirst gear 156 b and a second gear 184 b, each gear having a pluralityof teeth, are disposed on the first and second rotating elements 157 band 185 b, respectively. In the present embodiment, the motion transfermechanisms further include a first end-effector cable 158 b and a secondend-effector cable 186 b which are engaged with first and secondrotating elements 157 b and 185 b (coupled to the first and second gears156 b and 184 b, respectively) and the first and second working members148 b and 152 b as shown in FIG. 11. In the present embodiment, thefirst end-effector cable 158 b and a second end-effector cable 186 b arecables suitable for surgical applications. In other embodiments, thefirst and second end-effector cables 158 b and 186 b can be modified tobe a belt or chain. The end-effector assembly 136 b also includes a setscrew 149 b configured to adjust the tension of the first and secondend-effector cables 158 b and 186 b. Therefore, as the first and secondend-effector cables 158 b and 186 b wear and expand over time, the setscrew can be adjusted to maintain the required tension in the motiontransfer mechanisms.

Referring to FIG. 10, the first and second elongated elements 140 b and180 b extend between the end-effector assembly 136 b and the driveassembly (not shown). The first and second elongated elements 140 b and180 b are generally configured to support and control the end-effectorassembly 136 b. The first and second elongated elements 140 b and 180 beach include a motion transfer mechanism. In the present embodiment, themotion transfer mechanism of the first elongated element 140 b includesa gear 160 b having a plurality of teeth disposed thereon. The gear 160b is configured to mate with the first gear 156 b on the first rotatableelement 157 b of the end-effector assembly 136 b. The motion transfermechanism of the second elongated element 180 b includes a gear 188 bhaving a plurality of teeth 180 b disposed thereon. The gear 188 b isconfigured to mate with the second gear 184 b on the second rotatableelement 185 b of the end-effector assembly 136 b. It will now beappreciated that the gears 160 b and 188 b are configured to transferrotational motion of the first and second elongated elements 140 b and180 b to the first and second gears 156 b and 184 b to move,independently, the first and second rotatable elements 157 b and 185 b,respectively. In turn the first and second rotatable elements 157 b and185 b apply tension to the first and second end effector cables 158 band 185 b to move the working members 148 b and 152 b, respectively.

It will now be appreciated by a person skilled in the art with thebenefit of this description and the accompanying drawings that, in thepresent embodiment, the working members 148 b and 152 b can be pivotedabout the first axis 176 b (shown in FIG. 11) independently to open andclose the jaw. Furthermore, it will also now be appreciated that byusing first and second rotatable elements 157 b and 185 b in combinationwith the first and second end-effector cables 158 b and 186 b, the rangeof motion of the first and second working members 148 b and 152 b isincreased compared with the embodiment shown in FIG. 6 where the gears160 a and 188 a are sector gears.

Referring to FIGS. 12 to 16, another embodiment of a robotic instrument132 c is shown. Like components of the robotic instrument 132 c bearlike reference to their counterparts in the robotic arms 132 and 132 a,except followed by the suffix “c”. The robotic instrument 132 c includesan end-effector assembly 136 c, first, second, and third elongatedelements 140 c, 180 c, and 200 c respectively, and a drive assembly 144c.

In the present embodiment, the end-effector assembly 136 c is shown ingreater detail in FIG. 13. The end-effector assembly 136 c is generallyconfigured to interact with the patient P during MIS. The end-effectorassembly 136 c includes two working members 148 c and 152 c. Theend-effector assembly 136 c also includes two motion transfermechanisms. In the present embodiment, the transfer mechanisms are firstand second gears 156 c and 184 c each having a plurality of teeth. It isto be understood that the end-effector assembly 136 c, including theworking members 148 c and 152 c, is not particularly limited to anymaterial and that several different types of materials are contemplatedsuch as those contemplated for the end-effector assemblies 136 and 136a. The exact configuration of working members 148 c and 152 c is notparticularly limited. In the present embodiment shown in FIGS. 12 to 16,the working members 148 c and 152 c are jaws of forceps.

Referring to FIGS. 12 and 13, the first, second, and third elongatedelements 140 c, 1 BOc, and 200 c extend between the end-effectorassembly 136 c and the drive assembly 144 c. The first, second, andthird elongated elements 140 c, 180 c, and 200 c are generallyconfigured to support and control the end-effector assembly 136 c. It isto be understood that the first, second, and third elongated elements140 c, 180 c, and 200 c are not particularly limited to any one typematerial and that several different types of surgical-grade materialsare contemplated such as those contemplated for the elongated elements140, 140 a and 180 a. The first and second elongated elements 140 c and180 c each include two motion transfer mechanisms. In the presentembodiment, the motion transfer mechanisms of the first elongatedelement 140 c include first and second gears 160 c and 164 c each havinga plurality of teeth and disposed at opposite ends of the elongatedelement 140 c. The first gear 160 c is configured to mate with the firstgear 156 c of the end-effector assembly 136 c. The motion transfermechanisms of the second elongated element 180 c include first andsecond gears 188 c and 192 c each having a plurality of teeth and eachdisposed at opposite ends of the second elongated element 180 c. Thefirst gear 188 c is configured to mate with the second gear 184 c of theend-effector assembly 136 c. The third elongated element 200 c includesa motion transfer mechanism. In the present embodiment, the motiontransfer mechanism of the third elongated element 200 c is a gear 204 cdisposed the end of the third elongated element 200 c proximate to thedrive assembly 144 c. The opposite end 208 c of the third elongatedelement 200 c is connected to the end-effector assembly 136 c.

In certain embodiments, the first, second, and third elongated elements140 c, 180 c, and 200 c are each rigid, such that independently applyinga rotational torque about an axis 168 c at the gears 164 c, 192 c, and204 c will cause the first, second, and third elongated elements 140 c,180 c, and 200 c, respectively, to rotate independently from each otherwithout significant deformation. It will now be appreciated that thefirst gears 160 c and 188 c of the first and second elongated elements140 c and 180 c are configured to transfer rotational motion of thefirst and second elongated elements to the first and second gears 156 cand 184 c of the end effector assembly 136 c to move, independently, theworking members 148 c and 152 c, all respectively.

Referring to FIG. 15, the drive assembly 144 c of the present embodimentis shown in greater detail in FIG. 15. The drive assembly 144 c includesthree motion transfer mechanisms. In the present embodiment, thetransfer mechanisms are first, second, and third drive gears 172 c, 196c, and 212 c each having a plurality of teeth. The first, second, andthird drive gears 172 c, 196 c, and 212 c are configured to mate withthe gears 164 c, 192 c, and 204 c respectively. It will now beappreciated that the first, second, and third drive gears 172 c, 196 c,and 212 c are configured to transfer, independently, motion from thedrive assembly 144 c to a rotational motion of the first, second, andthird elongated elements 140 c, 180 c, and 200 c about the axis 168 c,respectively, by applying a rotational torque to the gears 164 c, 192 c,and 204 c, respectively. The first, second, and third drive gears 172 c,196 c, and 212 c can be driven, independently, by various means, such asthose discussed above in connection with drive assemblies 144 and 144 a.

In operation, the present embodiment of the robotic instrument 132 ccontrols the movement of the end-effector assembly 136 c, which includesthe movements of the working members 148 c and 152 c. A source of motionin the drive assembly 144 c rotates the first, second, and third drivegears 172 c, 196 c, and 212 c. The first, second, and third drive gears172 c, 196 c, and 212 c engage the gears 164 c, 192 c, and 204 c of thefirst, second and third elongated elements 140 c, 180 c, and 200 crespectively. Therefore, as the drive gear 172 c is rotated, engagementto second gear 164 c of the first elongated element 140 c will cause thefirst elongated element to rotate about the axis 168 c. The rotation ofthe first elongated element 140 c will cause a corresponding rotation ofthe first gear 160 c. The first gear 160 c engages the first gear 156 cof the end-effector assembly 136 c. Therefore, as the first gear 160 crotates, engagement to the first gear 156 c of the end-effector assembly136 c will cause the working member 148 c to pivot about a first axis176 c. Similarly, as the drive gear 196 c is rotated, engagement tosecond gear 192 c of the second elongated element 180 c will cause thesecond elongated element to rotate about the axis 168 c. The rotation ofthe second elongated element 180 c will cause a corresponding rotationof the first gear 188 c. The first gear 188 c engages the second gear184 c of the end-effector assembly 136 c. Therefore, as the first gear188 c rotates, engagement to the second gear 184 c of the end-effectorassembly 136 c will cause the working member 152 c to pivot about thefirst axis 176 c. As the drive gear 212 c is rotated, engagement to gear204 c of the third elongated element 200 c will cause the thirdelongated element to rotate about the axis 168 c. The rotation of thethird elongated element 200 c will cause a corresponding rotation of theend 208 c. Since the end 208 c is connected to the end-effector assembly136 c, rotation of the third elongated element 200 c will cause theend-effector assembly 136 c to rotate about the axis 168 c. It will nowbe appreciated by a person skilled in the art with the benefit of thisdescription and the accompanying drawings that, in the presentembodiment, the working members 148 c and 152 c can be pivoted about thefirst axis 176 c independently to open and close the jaw. It will alsonow be appreciated that since the end-effector assembly 136 c can berotated about the axis 168 c, the first axis 176 c is not necessarilyfixed and can be rotated as well.

Referring to FIG. 16, it will now be appreciated that the independentrotation of the end-effector assembly 136 c provides an addition degreeof freedom over the robotic instrument 132 a which involves rotating theworking members 148 c and 152 c about the axis 168 c as shown in FIG.16, where the axis 168 c is shown in FIGS. 12, 14, and 15. Therefore,independent control of the third elongated element 200 c allows theworking members 148 c and 152 c to reach over all angles about the axis168 c. This specific degree of freedom is referred to as a roll motion.It is to be understood that variations are contemplated whereby the axis168 c is not straight, such as the embodiment generally shown in FIG.24, which will be discussed later as an embodiment where the elongatedelement can be bent.

Variations are contemplated. For example, although the presentembodiment shows the first, second, and third elongated elements 140 c,180 c, and 200 c are nested tubes, it is to be understood that theembodiment is purely exemplary and it will be apparent to those skilledin the art that a variety of different configurations of the first,second, and third elongated elements 140 c, 180 c, and 200 c arecontemplated. In other embodiments, the first, second, and thirdelongated elements 140 c, 180 c, and 200 c, respectively, can bemodified such that they are not nested and instead are parallel andadjacent.

Referring to FIGS. 17 and 18, another embodiment of a robotic instrument132 d is shown Like components of the robotic instrument 132 d bear likereference to their counterparts in the robotic arms 132, 132 a and 132d, except followed by the suffix “d”. The robotic instrument 132 dincludes an end-effector assembly 136 d, first and second elongatedelements 140 d and 200 d respectively, and a drive assembly 144 d.

In the present embodiment, the end-effector assembly 136 d is shown ingreater detail in FIG. 18. The end-effector assembly 136 d is generallyconfigured to interact with the patient P during MIS. The end-effectorassembly 136 d includes a working member 148 d. The end-effectorassembly 136 d also includes a motion transfer mechanism. In the presentembodiment, the transfer mechanism is a gear 156 d having a plurality ofteeth. It is to be understood that the end-effector assembly 136 d,including the working member 148 d, is not particularly limited to anymaterial and that several different types of materials are contemplatedsuch as those contemplated for the end-effector assemblies 136, 136 a,and 136 c. The exact configuration of the working member 148 d is notparticularly limited. In the present embodiment shown in FIGS. 17 and18, the working member 148 d is a surgical blade capable of cauterizing.

Referring again to FIGS. 17 and 18, the first and second elongatedelements 140 d and 200 d extend between the end-effector assembly 136 dand the drive assembly 144 d. The first and second elongated elements140 d and 200 d are generally configured to support and control theend-effector assembly 136 d. It is to be understood that the first andsecond elongated elements 140 d and 200 d are not particularly limitedto any one type material and that several different types ofsurgical-grade materials are contemplated. The first elongated element140 d includes two motion transfer mechanisms. In the presentembodiment, the motion transfer mechanisms of the first elongatedelement 140 d include first and second gears 160 d and 164 d each havinga plurality of teeth and disposed at opposite ends of the elongatedelement 140 d. The first gear 160 d is configured to mate with the gear156 d of the end-effector assembly 136 d. The second elongated element200 d includes a motion transfer mechanism. In the present embodiment,the motion transfer mechanism of the second elongated element 200 d is agear 204 d disposed the end of the second elongated element 200 dproximate to the drive assembly 144 d. The opposite end 208 d of thesecond elongated element 200 d is connected to the end-effector assembly136 d.

In the present embodiment, the robotic instrument 132 d additionallyincludes an electrical wire 216 d extending through the first elongatedelement 140 d to the working member 148 d. The electrical wire 216 d isgenerally configured to supply an electrical current to the workingmember 148 d. The electrical current can be used to generate heat at theworking member 148 d to cauterize tissue when necessary. Although thepresent embodiment uses the electrical wire 216 d, the roboticinstrument can modified to provide the same functionality without anelectrical wire. For example, the first elongated element 140 d can bemade of stainless steel, which is electrically conductive. Therefore,the electrical conductivity of the first elongated element 140 d can beused in place of the electrical wire 216 d.

In certain embodiments, the first and second elongated elements 140 dand 200 d are each rigid, such that independently applying a rotationaltorque about an axis 168 d at the gears 164 d and 204 d will cause thefirst and second elongated elements 140 d and 200 d, respectively, torotate independently from each other without significant deformation. Itwill now be appreciated that the first gear 160 d of the first elongatedelements 140 d is configured to transfer rotational motion of the firstelongated element 140 d to the gear 156 d of the end-effector assembly136 d to move the working member 148 d.

Referring again to FIGS. 17 and 18, the drive assembly 144 d includestwo motion transfer mechanisms. In the present embodiment, the transfermechanisms are first and second drive gears 172 d and 212 d, each havinga plurality of teeth. The first and second drive gears 172 d and 212 dare configured to mate with the gears 164 d and 204 d respectively. Itwill now be appreciated that the first and second drive gears 172 a and212 d are configured to transfer, independently, motion from the driveassembly 144 d to a rotational motion of the first and second elongatedelements 140 d and 200 d about the axis 168 d, respectively, by applyinga rotational torque to the second gears 164 d and 204 d, respectively.The first and second drive gears 172 d and 212 d can be driven,independently, by various means, such as those discussed above inconnection with drive assemblies 144, 144 a, and 144 d.

In operation, the present embodiment of the robotic instrument 132 dcontrols the movement of the end-effector assembly 136 d, which includesthe movements of the working member 148 d. A source of motion in thedrive assembly 144 d rotates the first and second drive gears 172 d and212 d. The first and second drive gears 172 d and 212 d engage the gears164 d and 204 d of the first and second elongated elements 140 d and 200d respectively. Therefore, as the drive gear 172 d is rotated,engagement to gear 164 d of the first elongated element 140 d will causethe first elongated element to rotate about the axis 168 d. The rotationof the first elongated element 140 d will cause a corresponding rotationof the first gear 160 d. The gear 160 d engages the gear 156 d of theend-effector assembly 136 d. Therefore, as the gear 160 d rotates,engagement to the gear 156 d of the end-effector assembly 136 d willcause the working member 148 d to pivot about a first axis 176 d.Similarly, as the drive gear 212 d is rotated, engagement to gear 204 dof the second elongated element 200 d will cause the second elongatedelement to rotate about the axis 168 d. The rotation of the secondelongated element 200 d will cause a corresponding rotation of the end208 d. Since the end 208 d is connected to the end-effector assembly 136d, rotation of the second elongated element 200 d will cause theend-effector assembly 136 d to rotate about the axis 168 d. It will nowbe appreciated by a person skilled in the art with the benefit of thisdescription and the accompanying drawings that, in the presentembodiment, the working member 148 d can be pivoted about the first axis176 d independently from the rotation of the end-effector assembly 136d.

Variations are contemplated. For example, although the presentembodiment shows a single working member 148 d, the robotic instrument132 d can be modified to include a different number of working members.For example, previous embodiments show variations including two workingmembers. However, the number of working members are not limited to twoand a larger number of working members are contemplated.

Referring to FIG. 19, another embodiment of a robotic instrument 132 eis shown Like components of the robotic instrument 132 e bear likereference to their counterparts, except followed by the suffix “e”. Therobotic instrument 132 e includes an end-effector assembly 136 e, firstand second elongated elements 140 e and 180 e respectively, and a driveassembly (not shown).

Each elongated element 140 e and 180 e include a flexible portiondisposed generally at 220 e. The flexible portion allows for coarsemotion of the elongated elements 140 e and 180 e, which provides evenmore degrees of freedom to the robotic instrument 132 e. The flexibleportion can be provided by using laser cutting techniques on the firstand second elongated elements 140 e and 180. The first and second lasercut elongated elements 140 e and 180 may be obtained from Pulse Systems(Concord, Calif., U.S.A.) using uncut stainless steel tubes fromVitaNeedle (Needham, Mass., U.S.A.). By laser cutting a stainless steeltube, it has been found that the flexibility of the stainless steel tubedramatically increases without compromising the rotational rigidity.Therefore, the laser cut stainless steel tubes have been shown to workwell for providing flexibility, while still being effective attransferring rotational motion from a drive assembly to the end-effectorassembly 136 e. Although the laser cutting is shown in FIG. 19 to haveproduced spiral scores 224 e and 228 e on the first and second elongatedelements 140 e and 180 e, respectively, variations are contemplated. Itwill now be appreciated that different laser cut patterns can havedifferent characteristics and that the cut pattern selected depends onvarious factors.

It is also contemplated that other ways of providing a flexible portioncan be used. For example, the composition of the elongated elements 140e and 180 e can be varied such that a portion of each elongated element140 e and 180 e is more flexible than other portions.

FIGS. 20 and 21 provide view of another exemplary robotic instrument 132f and its associated end-effector assembly 136 f. The robotic instrument132 f includes an end-effector assembly 136 f and an elongated element140 f. The end-effector assembly 136 f is configured for another degreeof freedom. The rotational motion shown in FIG. 20 is a degree offreedom which involves rotating the end-effector assembly 136 f aboutthe second axis 232 f. In some embodiments, the second axis 232 f isperpendicular to the first axis 176 f to provide the robotic instrument132 f with the greatest range of motion. However, it is not essentialthat the second axis 232 f be perpendicular to the first axis 176 f. Forexample, similar to some of the previously discussed embodiments, thefirst axis 176 f can be rotatable relative to the second axis 232 f.

FIG. 21 shows another degree of freedom involving a longitudinaltranslation motion allowing the robotic instrument 132 f to betranslated along axis 168 f. For example, this allows the roboticinstrument 132 f to enter and penetrate deeper into the body, or beretracted. Unlike the other degrees of freedom discussed, thistranslational degree of freedom is provided by a system on the roboticarm 128. For example, the robotic arm can include a z-rail system (notshown) for moving the entire robotic instrument 132 f.

FIGS. 22 and 23 provide view of another exemplary robotic instrument 132g and its associated end-effector assembly 136 g. The robotic instrument132 g includes an end-effector assembly 136 g and an elongated element140 g. The end-effector assembly 136 g is configured for another degreeof freedom similar to the end-effector assembly 136 f.

FIG. 23 shows another degree of freedom involving a longitudinaltranslation motion allowing the robotic instrument 132 g to betranslated along axis 168 g. For example, this allows the roboticinstrument 132 g to enter and penetrate deeper into the body, or beretracted. For example, the robotic arm can include a z-rail system (notshown) for moving the entire robotic instrument 132 g.

It is to be understood that degrees of freedom allow for a range ofmovements for facilitating MIS. Variations are contemplated andadditional degrees of freedom not discussed in this application can beadded. For example, the robotic instrument 132 f can be externally movedusing the robotic arm 128 or other suitable means. Therefore, the motionof the robotic arm 128 can move the end-effector assembly 136 f over alarge distance as an additional degree of freedom.

Referring to FIG. 24, another embodiment of a robotic instrument 132 his shown Like components of the robotic arm 132 h bear like reference totheir counterparts, except followed by the suffix “h”. The roboticinstrument 132 h includes an end-effector assembly 136 h, first, second,and third elongated elements (not shown) encased in a cover 240 h, and adrive assembly 144 h. In this particular embodiment, the roboticinstrument 132 h includes a flexible portion 220 h configured to providecoarse motion proximate to the end-effector assembly 136 h. The flexibleportion 220 h is located between the cover 240 h and the end-effectorassembly 136 h.

The flexible portion 220 h includes first and second subsections 244 hand 248 h. Each of the first and second subsections 244 h and 248 h isgenerally configured to bend within first and second coarse motionplanes, respectively. It is to be understood that the first, second, andthird elongated elements (not shown} are consequently bent when thefirst and second subsections 244 h and 248 h are bent such that thefirst, second, and third elongated elements can independently rotatewhile bent. Furthermore, the motion of the first subsection 244 h andthe second subsection 248 h are independent such that one or both of thefirst and second subsections may be bent independently. Therefore, it isto be understood that the coarse motion of the robotic instrument 132 hcan be controlled using a set of at least one course motion adjustmentcable 236 h for each of subsection 244 h and 248 h by independentlyadjusting the tension of each set of at least one course motionadjustment cable.

Referring again to FIG. 24, in the present embodiment, the first andsecond coarse motion planes are substantially perpendicular to eachother. However, it is to be appreciated that the first and second coarsemotion planes do not need to be perpendicular to each other and can beat any angle in some embodiments. Furthermore, the exact configurationof first and second subsections 244 h and 248 h is not particularlylimited. In the present embodiment, there are two subsections 244 h and248 h. In other embodiments, it is to be understood that the flexibleportion 220 h can be modified to include more subsections to providemore coarse motion planes within which subsections of the flexibleportion 220 h can bend. In addition, the subsections need not be placeadjacent to each other. Alternatively, it is also to be understood thatthe flexible portion 220 h can be modified to include only onesubsection to provide a single coarse motion plane.

In addition, the robotic instrument 132 h includes an outer cover 240 h.It is to be appreciated that the outer cover 240 h can be rigid toprovide support for the elongated elements (not shown) within the outercover. In addition, the plurality of coarse motion adjustment cables 236h can be disposed within the outer cover 240 h in a pace between theinside wall of the outer cover and the elongated elements. By placingthe coarse motion adjustment cables 236 h behind an outer cover, it isto be understood that wear on the cables is reduced. Furthermore, in theembodiment shown in FIG. 24, the outer cover 240 h is fixed. That is,the outer cover 240 h does not rotate. It will now be appreciated thatwhen the robotic instrument 132 t is inserted inside the patient P, theouter cover 240 h reduces the chance of the robotic instrument 132 hgetting caught on something to cause damage.

It will now be appreciated that each subsection 244 h and 248 h willprovide an additional degree of freedom. Referring back to FIG. 24, itwill also now be apparent that the first and second subsections 244 hand 248 h add two more degrees of freedom to the robotic instrument 132h. Therefore, the robotic instrument 132 h includes six degrees offreedom. The six degrees of freedom include the roll about the axis 168h (where the first, second, and third elongated elements rotateconcurrently), rotation of the end-effector assembly 136 h about asecond axis 232 h, rotation of a first working member 148 h about afirst axis 176 h, rotation of a second working member 152 h about thefirst axis 176 h, the bending of the first subsection 244 h and thebending of the second subsection 248 h. In addition, the entire roboticinstrument 132 h can be moved on a rail system (not shown) to provide aseventh degree of freedom.

It is to be understood that by moving the first and second workingmembers 148 h and 152 h together by rotating the first and secondelongated elements, the working members 148 h and 152 h can rotatetogether about the first axis 176 h such that the working members 148 hand 152 h can open and close over a range of angles about the first axis176 h. Furthermore, it will also be appreciated that to change the angleabout the first axis 176 h at which the working members 148 h and 152 hopen and close, the first and second elongated elements rotate at adifferent amount compared with the third elongated element. Thisdifferent amount is called a delta and can be adjusted to control themovement of the end effector assembly 136 h relative to the roboticinstrument 132 h.

Referring to FIG. 25, another embodiment of a robotic instrument 132 iis shown Like components of the robotic arm 132 i bear like reference totheir counterparts, except followed by the suffix “i”. The roboticinstrument 132 i includes an end-effector assembly 136 i, first, second,and third elongated elements (not shown) encased in a cover 240 i, and adrive assembly 144 i. In this particular embodiment, the roboticinstrument 132 i includes a flexible portion 220 i configured to providecoarse motion proximate to the end-effector assembly 136 i in a similarmanner to the flexible portion 220 h in the robotic instrument 132 h.The flexible portion 220 i is located between the cover 240 i and theend-effector assembly 136 i. The end-effector assembly 136 i is similarto the end-effector assembly 136 b described. Therefore, the roboticinstrument 132 i shown in FIG. 23 adds coarse motion to the end-effectorassembly 136 b.

Referring again to FIG. 22, it will now be appreciated that if the rollmotion rotates the first axis 176 g relative to the second axis 232 g,the robotic instrument 132 g would have positions where the first axis176 g can be parallel to the second axis 2329. However, in theembodiment shown in FIG. 25, the roll motion rotates both the first axis176 i and the second axis 232 i by having the rotation occur between theflexible portion 220 i and the second axis 232 i. Therefore, the anglebetween the first axis 176 h and the second axis 232 i remains fixed. Inthe present embodiment, the angle between the first axis 176 i and thesecond axis 232 i is maintained at 90 degrees. However, in otherembodiments, the angle can be greater or smaller than 90 degrees.

Therefore, it is to be understood that many combinations, variations andsubsets of the embodiments and teachings herein are contemplated. As anon-limiting example, the robotic instrument 132 d can be modified withthe variation described in relation to the robotic instrument 132 g toprovide for coarse motion in the robotic instrument 132 d. As anothernonlimiting example, the robotic instrument 132 can be modified with thevariation described in relation to the robotic instrument 132 d toprovide cauterizing functionality to the robotic instrument 132.

While specific embodiments have been described and illustrated, suchembodiments should be considered illustrative only and should not serveto limit the accompanying claims.

1. (canceled)
 2. A robotic surgical instrument, comprising: anend-effector assembly comprising a working member configured to pivotabout a first axis; an elongated element extending between a proximalend and a distal end, the distal end being affixed with respect to theend effector assembly to hold the first axis perpendicular to theelongated element; a second elongated element extending between aproximal end and a distal end, the distal end of the second elongatedelement being coupled with the end effector assembly so that rotation ofthe second elongated element about a second axis pivots the workingmember about the first axis; and a drive assembly comprising a firstdrive member coupled to the proximal end of the elongated element and asecond drive member coupled to the proximal end of the second elongatedelement, the drive assembly configured to selectively operate the firstdrive member to rotate the elongated element and configured toselectively operate the second drive member to rotate the secondelongated element, wherein the elongated element and second elongatedelement are nested together.
 3. The robotic surgical instrument of claim2, wherein the working member is a blade.
 4. The robotic surgicalinstrument of claim 2, wherein the working member is configured tocauterize a tissue.
 5. The robotic surgical instrument of claim 2,wherein one or both of the elongate member and the second elongatemember comprises a flexible portion.
 6. The robotic surgical instrumentof claim 2, wherein one or both of the first and second drive memberscomprise a gear.
 7. The robotic surgical instrument of claim 2, whereinone or both of the first and second drive members rotate about a thirdaxis offset from and the second axis.
 8. The robotic surgical instrumentof claim 2, further comprising an electrical wire extending through thesecond elongated element and coupled to the working member.
 9. Therobotic surgical instrument of claim 2, wherein one or both of theelongated element and the second elongated element comprises a tube. 10.The robotic surgical instrument of claim 2, wherein the distal end ofthe second elongated element is coupled to the working member of theend-effector assembly via a gear.
 11. A robotic surgical system,comprising: a support arm; and a surgical instrument coupled to thesupport arm, the surgical instrument comprising an end-effector assemblycomprising a working member configured to pivot about a first axis, anelongated element extending between a proximal end and a distal end, thedistal end being affixed with respect to the end effector assembly tohold the first axis perpendicular to the elongated element, a secondelongated element extending between a proximal end and a distal end, thedistal end of the second elongated element being coupled with the endeffector assembly so that rotation of the second elongated element abouta second axis pivots the working member about the first axis, and adrive assembly comprising a first drive member coupled to the proximalend of the elongated element and a second drive member coupled to theproximal end of the second elongated element, the drive assemblyconfigured to selectively operate the first drive member to rotate theelongated element and configured to selectively operate the second drivemember to rotate the second elongated element, wherein the elongatedelement and second elongated element are nested together.
 12. Therobotic surgical system of claim 11, wherein the surgical instrument ismovably coupled to the support arm.
 13. The robotic surgical system ofclaim 11, wherein the support arm is a robotic arm configured to move inresponse to an input control signal received from an input deviceoperated by a user.
 14. The robotic surgical system of claim 11, whereinthe working member is a blade.
 15. The robotic surgical instrument ofclaim 11, wherein the working member is configured to cauterize atissue.
 16. The robotic surgical instrument of claim 11, wherein one orboth of the elongate member and the second elongate member comprises aflexible portion.
 17. The robotic surgical instrument of claim 11,wherein one or both of the first and second drive members comprise agear.
 18. The robotic surgical instrument of claim 11, wherein one orboth of the first and second drive members rotate about a third axisoffset from and the second axis.
 19. The robotic surgical instrument ofclaim 11, further comprising an electrical wire extending through thesecond elongated element and coupled to the working member.
 20. Therobotic surgical instrument of claim 2, wherein one or both of theelongated element and the second elongated element comprises a tube. 21.The robotic surgical instrument of claim 2, wherein the distal end ofthe second elongated element is coupled to the working member of theend-effector assembly via a gear.